Any recommendations for a good Windows email client that supports IMAP well and runs as a portable application (i.e. you can run it from disk without installation)?
I've been using ThunderbirdPortable, but it's IMAP support is very flakey (lots of problems with attachments from an IMAP server) and I really need to find something better. It's important that it be portable because I'm constantly rebooting into alternate boot environments and want to share the email program among all of the various Windows instances.
I don't need a lot of functionality -- something akin to the iPhone mail application is fine, I don't need (or particularly want) lots of features.